Cambridge IGCSE (9-1) Physics 0972 Formula & Key Numbers Reference Flashcards

Comprehensive formula and key numerical constants for Cambridge IGCSE (9–1) Physics 0972, including Core and Extended (Supplement) content.

What is the formula for speed?

$v = \frac{s}{t}$, where $v$ is speed, $s$ is distance, and $t$ is time.

How is average speed calculated when speed is not constant?

$$v_{avg} = \frac{\text{total distance}}{\text{total time}}$$

What is the formula for acceleration ($a$) given the change in velocity ($\Delta v$)?

$$a = \frac{\Delta v}{\Delta t}$$

How is gravitational field strength ($g$) calculated from weight ($W$) and mass ($m$)?

$$g = \frac{W}{m}$$

What is the constant value for gravitational field strength ($g$) at Earth's surface?

$g \approx 9.8\, \text{N/kg}$ (or $9.8\, \text{m/s}^2$)

What is the formula for density ($\rho$)?

$$\rho = \frac{m}{V}$$

What is Hooke’s Law formula for the spring constant ($k$)?

$k = \frac{F}{x}$ where $F$ is force and $x$ is extension.

What is the formula for Newton’s second law?

$F = m \times a$ where $F$ is the resultant force.

What is the formula for the moment of a force ($M$)?

$M = F \times d$ where $d$ is the perpendicular distance from the pivot.

What is the formula for momentum ($p$)?

$$p = m \times v$$

How is Impulse defined in terms of force and time?

$\text{Impulse} = F \times \Delta t$ and is equivalent to the change in momentum $\Delta(mv)$.Array

What is the formula for kinetic energy ($E_k$)?

$$E_k = \frac{1}{2} m v^2$$

What is the formula for gravitational potential energy change ($\Delta E_p$)?

$$\Delta E_p = m g \Delta h$$

What is the formula for work done ($W$)?

$W = F \times d$ where $d$ is distance in the direction of the force.

What are the two formulas for power ($P$)?

$P = \frac{W}{t}$ or $P = \frac{\Delta E}{t}$

How is percentage efficiency (energy) calculated?

$$\% \text{ efficiency} = \frac{E_{useful}}{E_{total}} \times 100$$

What is the basic formula for pressure ($p$)?

$$p = \frac{F}{A}$$

What is the formula for pressure change ($\Delta p$) with depth in a liquid?

$$\Delta p = \rho g \Delta h$$

What is the formula for converting Celsius ($\theta$) to Kelvin ($T$)?

$$T(K) = \theta(^{\circ}\text{C}) + 273$$

What is the formula for Boyle’s Law?

$p_1 V_1 = p_2 V_2$ at constant temperature.

What is the formula for specific heat capacity ($c$)?

$$c = \frac{\Delta E}{m \Delta \theta}$$

What is the formula for wave speed ($v$)?

$$v = f \lambda$$

What is Snell’s Law for refractive index ($n$)?

$$n = \frac{\sin(i)}{\sin(r)}$$

What is the formula for the critical angle ($c$)?

$$n = \frac{1}{\sin(c)}$$

What is the formula for electric current ($I$)?

$$I = \frac{Q}{t}$$

What is the formula for electromotive force ($E$)?

$$E = \frac{W}{Q}$$

What is the formula for resistance ($R$)?

$$R = \frac{V}{I}$$

What is the formula for electrical power ($P$) using voltage and current?

$$P = I \times V$$

What is the derived formula for electrical power using resistance?

$$P = I^2 R$$

What is the formula for total resistance ($R_T$) in a series circuit?

$$R_T = R_1 + R_2 + \dots$$

What is the constant power-loss formula for total resistance ($R_T$) of two resistors in parallel?

$$R_T = \frac{R_1 \times R_2}{R_1 + R_2}$$

What is the potential divider formula?

$$\frac{R_1}{R_2} = \frac{V_1}{V_2}$$

What is the relationship between transformer voltage and coil turns?

$$\frac{V_p}{V_s} = \frac{N_p}{N_s}$$

What is the formula for an ideal (100% efficient) transformer?

$$I_p V_p = I_s V_s$$

What is the half-life relationship formula for the number of nuclei remaining ($N$)?

$$N = N_0 \times (\frac{1}{2})^n$$

What is the formula for average orbital speed ($v$)?

$$v = \frac{2 \pi r}{T}$$

What is the equation for Hubble’s Law?

$$H_0 = \frac{v}{d}$$

What is the estimated age of the universe according to the Hubble constant ($H_0$)?

$$\text{Age} \approx \frac{1}{H_0}$$

What is the speed of light in vacuum ($c$)?

$$3.0 \times 10^8\, \text{m/s}$$

What is absolute zero in degrees Celsius?

$$-273^{\circ}\text{C}$$

What is the value of the Hubble constant ($H_0$)?

$$2.2 \times 10^{-18}\, \text{s}^{-1}$$

What is the audible frequency range for human hearing?

$$20\, \text{Hz} - 20000\, \text{Hz}$$

What is the approximate speed of sound in air at room temperature?

$$330–350\, \text{m/s}$$

What is the approximate diameter of the Milky Way?

$$100000 \text{ light-years}$$